<?php
/**
 *    PHPExcel
 *
 *    Copyright (c) 2006 - 2013 PHPExcel
 *
 *    This library is free software; you can redistribute it and/or
 *    modify it under the terms of the GNU Lesser General Public
 *    License as published by the Free Software Foundation; either
 *    version 2.1 of the License, or (at your option) any later version.
 *
 *    This library is distributed in the hope that it will be useful,
 *    but WITHOUT ANY WARRANTY; without even the implied warranty of
 *    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
 *    Lesser General Public License for more details.
 *
 *    You should have received a copy of the GNU Lesser General Public
 *    License along with this library; if not, write to the Free Software
 *    Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301  USA
 *
 * @category     PHPExcel
 * @package      PHPExcel_Cell
 * @copyright    Copyright (c) 2006 - 2013 PHPExcel (http://www.codeplex.com/PHPExcel)
 * @license      http://www.gnu.org/licenses/old-licenses/lgpl-2.1.txt	LGPL
 * @version      1.7.9, 2013-06-02
 */


/**
 *    PHPExcel_Cell
 *
 * @category   PHPExcel
 * @package    PHPExcel_Cell
 * @copyright  Copyright (c) 2006 - 2013 PHPExcel (http://www.codeplex.com/PHPExcel)
 */
class PHPExcel_Cell {

	/**
	 *  Default range variable constant
	 *
	 * @var  string
	 */
	const DEFAULT_RANGE = 'A1:A1';

	/**
	 *    Value binder to use
	 *
	 * @var    PHPExcel_Cell_IValueBinder
	 */
	private static $_valueBinder = null;

	/**
	 *    Value of the cell
	 *
	 * @var    mixed
	 */
	private $_value;

	/**
	 *    Calculated value of the cell (used for caching)
	 *    This returns the value last calculated by MS Excel or whichever spreadsheet program was used to
	 *        create the original spreadsheet file.
	 *    Note that this value is not guaranteed to reflect the actual calculated value because it is
	 *        possible that auto-calculation was disabled in the original spreadsheet, and underlying data
	 *        values used by the formula have changed since it was last calculated.
	 *
	 * @var mixed
	 */
	private $_calculatedValue = null;

	/**
	 *    Type of the cell data
	 *
	 * @var    string
	 */
	private $_dataType;

	/**
	 *    Parent worksheet
	 *
	 * @var    PHPExcel_CachedObjectStorage_CacheBase
	 */
	private $_parent;

	/**
	 *    Index to cellXf
	 *
	 * @var    int
	 */
	private $_xfIndex;

	/**
	 *    Attributes of the formula
	 *
	 */
	private $_formulaAttributes;


	/**
	 *    Send notification to the cache controller
	 *
	 * @return void
	 **/
	public function notifyCacheController() {
		$this->_parent->updateCacheData($this);

		return $this;
	}

	public function detach() {
		$this->_parent = null;
	}

	public function attach(PHPExcel_CachedObjectStorage_CacheBase $parent) {


		$this->_parent = $parent;
	}


	/**
	 *    Create a new Cell
	 *
	 * @param    mixed              $pValue
	 * @param    string             $pDataType
	 * @param    PHPExcel_Worksheet $pSheet
	 *
	 * @throws    PHPExcel_Exception
	 */
	public function __construct($pValue = null, $pDataType = null, PHPExcel_Worksheet $pSheet = null) {
		// Initialise cell value
		$this->_value = $pValue;

		// Set worksheet cache
		$this->_parent = $pSheet->getCellCacheController();

		// Set datatype?
		if ($pDataType !== null)
		{
			if ($pDataType == PHPExcel_Cell_DataType::TYPE_STRING2)
				$pDataType = PHPExcel_Cell_DataType::TYPE_STRING;
			$this->_dataType = $pDataType;
		}
		else
		{
			if (!self::getValueBinder()->bindValue($this, $pValue))
			{
				throw new PHPExcel_Exception("Value could not be bound to cell.");
			}
		}

		// set default index to cellXf
		$this->_xfIndex = 0;
	}

	/**
	 *    Get cell coordinate column
	 *
	 * @return    string
	 */
	public function getColumn() {
		return $this->_parent->getCurrentColumn();
	}

	/**
	 *    Get cell coordinate row
	 *
	 * @return    int
	 */
	public function getRow() {
		return $this->_parent->getCurrentRow();
	}

	/**
	 *    Get cell coordinate
	 *
	 * @return    string
	 */
	public function getCoordinate() {
		return $this->_parent->getCurrentAddress();
	}

	/**
	 *    Get cell value
	 *
	 * @return    mixed
	 */
	public function getValue() {
		return $this->_value;
	}

	/**
	 *    Get cell value with formatting
	 *
	 * @return    string
	 */
	public function getFormattedValue() {
		return (string)PHPExcel_Style_NumberFormat::toFormattedString($this->getCalculatedValue(), $this->getWorksheet()->getParent()->getCellXfByIndex($this->getXfIndex())->getNumberFormat()
																										->getFormatCode());
	}

	/**
	 *    Set cell value
	 *
	 *    Sets the value for a cell, automatically determining the datatype using the value binder
	 *
	 * @param    mixed $pValue Value
	 *
	 * @return    PHPExcel_Cell
	 * @throws    PHPExcel_Exception
	 */
	public function setValue($pValue = null) {
		if (!self::getValueBinder()->bindValue($this, $pValue))
		{
			throw new PHPExcel_Exception("Value could not be bound to cell.");
		}

		return $this;
	}

	/**
	 *    Set the value for a cell, with the explicit data type passed to the method (bypassing any use of the value binder)
	 *
	 * @param    mixed  $pValue    Value
	 * @param    string $pDataType Explicit data type
	 *
	 * @return    PHPExcel_Cell
	 * @throws    PHPExcel_Exception
	 */
	public function setValueExplicit($pValue = null, $pDataType = PHPExcel_Cell_DataType::TYPE_STRING) {
		// set the value according to data type
		switch ($pDataType)
		{
			case PHPExcel_Cell_DataType::TYPE_STRING2:
				$pDataType = PHPExcel_Cell_DataType::TYPE_STRING;
			case PHPExcel_Cell_DataType::TYPE_STRING:
			case PHPExcel_Cell_DataType::TYPE_NULL:
			case PHPExcel_Cell_DataType::TYPE_INLINE:
				$this->_value = PHPExcel_Cell_DataType::checkString($pValue);
				break;
			case PHPExcel_Cell_DataType::TYPE_NUMERIC:
				$this->_value = (float)$pValue;
				break;
			case PHPExcel_Cell_DataType::TYPE_FORMULA:
				$this->_value = (string)$pValue;
				break;
			case PHPExcel_Cell_DataType::TYPE_BOOL:
				$this->_value = (bool)$pValue;
				break;
			case PHPExcel_Cell_DataType::TYPE_ERROR:
				$this->_value = PHPExcel_Cell_DataType::checkErrorCode($pValue);
				break;
			default:
				throw new PHPExcel_Exception('Invalid datatype: ' . $pDataType);
				break;
		}

		// set the datatype
		$this->_dataType = $pDataType;

		return $this->notifyCacheController();
	}

	/**
	 *    Get calculated cell value
	 *
	 * @deprecated        Since version 1.7.8 for planned changes to cell for array formula handling
	 *
	 * @param    boolean $resetLog Whether the calculation engine logger should be reset or not
	 *
	 * @return    mixed
	 * @throws    PHPExcel_Exception
	 */
	public function getCalculatedValue($resetLog = true) {
		//echo 'Cell '.$this->getCoordinate().' value is a '.$this->_dataType.' with a value of '.$this->getValue().PHP_EOL;
		if ($this->_dataType == PHPExcel_Cell_DataType::TYPE_FORMULA)
		{
			try
			{
				//echo 'Cell value for '.$this->getCoordinate().' is a formula: Calculating value'.PHP_EOL;
				$result = PHPExcel_Calculation::getInstance($this->getWorksheet()->getParent())->calculateCellValue($this, $resetLog);
				//echo $this->getCoordinate().' calculation result is '.$result.PHP_EOL;
				//	We don't yet handle array returns
				if (is_array($result))
				{
					while (is_array($result))
					{
						$result = array_pop($result);
					}
				}
			} catch (PHPExcel_Exception $ex)
			{
				if (($ex->getMessage() === 'Unable to access External Workbook') && ($this->_calculatedValue !== null))
				{
					//echo 'Returning fallback value of '.$this->_calculatedValue.' for cell '.$this->getCoordinate().PHP_EOL;
					return $this->_calculatedValue; // Fallback for calculations referencing external files.
				}
				//echo 'Calculation Exception: '.$ex->getMessage().PHP_EOL;
				$result = '#N/A';
				throw new PHPExcel_Calculation_Exception($this->getWorksheet()->getTitle() . '!' . $this->getCoordinate() . ' -> ' . $ex->getMessage());
			}

			if ($result === '#Not Yet Implemented')
			{
				//echo 'Returning fallback value of '.$this->_calculatedValue.' for cell '.$this->getCoordinate().PHP_EOL;
				return $this->_calculatedValue; // Fallback if calculation engine does not support the formula.
			}

			//echo 'Returning calculated value of '.$result.' for cell '.$this->getCoordinate().PHP_EOL;
			return $result;
		}
		elseif ($this->_value instanceof PHPExcel_RichText)
		{
			//		echo 'Cell value for '.$this->getCoordinate().' is rich text: Returning data value of '.$this->_value.'<br />';
			return $this->_value->getPlainText();
		}

		//		echo 'Cell value for '.$this->getCoordinate().' is not a formula: Returning data value of '.$this->_value.'<br />';
		return $this->_value;
	}

	/**
	 *    Set old calculated value (cached)
	 *
	 * @param    mixed $pValue Value
	 *
	 * @return    PHPExcel_Cell
	 */
	public function setCalculatedValue($pValue = null) {
		if ($pValue !== null)
		{
			$this->_calculatedValue = (is_numeric($pValue)) ? (float)$pValue : $pValue;
		}

		return $this->notifyCacheController();
	}

	/**
	 *    Get old calculated value (cached)
	 *    This returns the value last calculated by MS Excel or whichever spreadsheet program was used to
	 *        create the original spreadsheet file.
	 *    Note that this value is not guaranteed to refelect the actual calculated value because it is
	 *        possible that auto-calculation was disabled in the original spreadsheet, and underlying data
	 *        values used by the formula have changed since it was last calculated.
	 *
	 * @return    mixed
	 */
	public function getOldCalculatedValue() {
		return $this->_calculatedValue;
	}

	/**
	 *    Get cell data type
	 *
	 * @return string
	 */
	public function getDataType() {
		return $this->_dataType;
	}

	/**
	 *    Set cell data type
	 *
	 * @param    string $pDataType
	 *
	 * @return    PHPExcel_Cell
	 */
	public function setDataType($pDataType = PHPExcel_Cell_DataType::TYPE_STRING) {
		if ($pDataType == PHPExcel_Cell_DataType::TYPE_STRING2)
			$pDataType = PHPExcel_Cell_DataType::TYPE_STRING;

		$this->_dataType = $pDataType;

		return $this->notifyCacheController();
	}

	/**
	 *    Does this cell contain Data validation rules?
	 *
	 * @return    boolean
	 * @throws    PHPExcel_Exception
	 */
	public function hasDataValidation() {
		if (!isset($this->_parent))
		{
			throw new PHPExcel_Exception('Cannot check for data validation when cell is not bound to a worksheet');
		}

		return $this->getWorksheet()->dataValidationExists($this->getCoordinate());
	}

	/**
	 *    Get Data validation rules
	 *
	 * @return    PHPExcel_Cell_DataValidation
	 * @throws    PHPExcel_Exception
	 */
	public function getDataValidation() {
		if (!isset($this->_parent))
		{
			throw new PHPExcel_Exception('Cannot get data validation for cell that is not bound to a worksheet');
		}

		return $this->getWorksheet()->getDataValidation($this->getCoordinate());
	}

	/**
	 *    Set Data validation rules
	 *
	 * @param    PHPExcel_Cell_DataValidation $pDataValidation
	 *
	 * @return    PHPExcel_Cell
	 * @throws    PHPExcel_Exception
	 */
	public function setDataValidation(PHPExcel_Cell_DataValidation $pDataValidation = null) {
		if (!isset($this->_parent))
		{
			throw new PHPExcel_Exception('Cannot set data validation for cell that is not bound to a worksheet');
		}

		$this->getWorksheet()->setDataValidation($this->getCoordinate(), $pDataValidation);

		return $this->notifyCacheController();
	}

	/**
	 *    Does this cell contain a Hyperlink?
	 *
	 * @return boolean
	 * @throws    PHPExcel_Exception
	 */
	public function hasHyperlink() {
		if (!isset($this->_parent))
		{
			throw new PHPExcel_Exception('Cannot check for hyperlink when cell is not bound to a worksheet');
		}

		return $this->getWorksheet()->hyperlinkExists($this->getCoordinate());
	}

	/**
	 *    Get Hyperlink
	 *
	 * @return    PHPExcel_Cell_Hyperlink
	 * @throws    PHPExcel_Exception
	 */
	public function getHyperlink() {
		if (!isset($this->_parent))
		{
			throw new PHPExcel_Exception('Cannot get hyperlink for cell that is not bound to a worksheet');
		}

		return $this->getWorksheet()->getHyperlink($this->getCoordinate());
	}

	/**
	 *    Set Hyperlink
	 *
	 * @param    PHPExcel_Cell_Hyperlink $pHyperlink
	 *
	 * @return    PHPExcel_Cell
	 * @throws    PHPExcel_Exception
	 */
	public function setHyperlink(PHPExcel_Cell_Hyperlink $pHyperlink = null) {
		if (!isset($this->_parent))
		{
			throw new PHPExcel_Exception('Cannot set hyperlink for cell that is not bound to a worksheet');
		}

		$this->getWorksheet()->setHyperlink($this->getCoordinate(), $pHyperlink);

		return $this->notifyCacheController();
	}

	/**
	 *    Get parent worksheet
	 *
	 * @return PHPExcel_Worksheet
	 */
	public function getParent() {
		return $this->_parent;
	}

	/**
	 *    Get parent worksheet
	 *
	 * @return PHPExcel_Worksheet
	 */
	public function getWorksheet() {
		return $this->_parent->getParent();
	}

	/**
	 *    Get cell style
	 *
	 * @return    PHPExcel_Style
	 */
	public function getStyle() {
		return $this->getWorksheet()->getParent()->getCellXfByIndex($this->getXfIndex());
	}

	/**
	 *    Re-bind parent
	 *
	 * @param    PHPExcel_Worksheet $parent
	 *
	 * @return    PHPExcel_Cell
	 */
	public function rebindParent(PHPExcel_Worksheet $parent) {
		$this->_parent = $parent->getCellCacheController();

		return $this->notifyCacheController();
	}

	/**
	 *    Is cell in a specific range?
	 *
	 * @param    string $pRange Cell range (e.g. A1:A1)
	 *
	 * @return    boolean
	 */
	public function isInRange($pRange = 'A1:A1') {
		list($rangeStart, $rangeEnd) = self::rangeBoundaries($pRange);

		// Translate properties
		$myColumn = self::columnIndexFromString($this->getColumn());
		$myRow = $this->getRow();

		// Verify if cell is in range
		return (($rangeStart[0] <= $myColumn) && ($rangeEnd[0] >= $myColumn) && ($rangeStart[1] <= $myRow) && ($rangeEnd[1] >= $myRow));
	}

	/**
	 *    Coordinate from string
	 *
	 * @param    string $pCoordinateString
	 *
	 * @return    array    Array containing column and row (indexes 0 and 1)
	 * @throws    PHPExcel_Exception
	 */
	public static function coordinateFromString($pCoordinateString = 'A1') {
		if (preg_match("/^([$]?[A-Z]{1,3})([$]?\d{1,7})$/", $pCoordinateString, $matches))
		{
			return array($matches[1], $matches[2]);
		}
		elseif ((strpos($pCoordinateString, ':') !== false) || (strpos($pCoordinateString, ',') !== false))
		{
			throw new PHPExcel_Exception('Cell coordinate string can not be a range of cells');
		}
		elseif ($pCoordinateString == '')
		{
			throw new PHPExcel_Exception('Cell coordinate can not be zero-length string');
		}

		throw new PHPExcel_Exception('Invalid cell coordinate ' . $pCoordinateString);
	}

	/**
	 *    Make string row, column or cell coordinate absolute
	 *
	 * @param    string $pCoordinateString e.g. 'A' or '1' or 'A1'
	 *                                     Note that this value can be a row or column reference as well as a cell reference
	 *
	 * @return    string    Absolute coordinate        e.g. '$A' or '$1' or '$A$1'
	 * @throws    PHPExcel_Exception
	 */
	public static function absoluteReference($pCoordinateString = 'A1') {
		if (strpos($pCoordinateString, ':') === false && strpos($pCoordinateString, ',') === false)
		{
			// Split out any worksheet name from the reference
			$worksheet = '';
			$cellAddress = explode('!', $pCoordinateString);
			if (count($cellAddress) > 1)
			{
				list($worksheet, $pCoordinateString) = $cellAddress;
			}
			if ($worksheet > '')
				$worksheet .= '!';

			// Create absolute coordinate
			if (ctype_digit($pCoordinateString))
			{
				return $worksheet . '$' . $pCoordinateString;
			}
			elseif (ctype_alpha($pCoordinateString))
			{
				return $worksheet . '$' . strtoupper($pCoordinateString);
			}

			return $worksheet . self::absoluteCoordinate($pCoordinateString);
		}

		throw new PHPExcel_Exception('Cell coordinate string can not be a range of cells');
	}

	/**
	 *    Make string coordinate absolute
	 *
	 * @param    string $pCoordinateString e.g. 'A1'
	 *
	 * @return    string    Absolute coordinate        e.g. '$A$1'
	 * @throws    PHPExcel_Exception
	 */
	public static function absoluteCoordinate($pCoordinateString = 'A1') {
		if (strpos($pCoordinateString, ':') === false && strpos($pCoordinateString, ',') === false)
		{
			// Split out any worksheet name from the coordinate
			$worksheet = '';
			$cellAddress = explode('!', $pCoordinateString);
			if (count($cellAddress) > 1)
			{
				list($worksheet, $pCoordinateString) = $cellAddress;
			}
			if ($worksheet > '')
				$worksheet .= '!';

			// Create absolute coordinate
			list($column, $row) = self::coordinateFromString($pCoordinateString);
			$column = ltrim($column, '$');
			$row = ltrim($row, '$');

			return $worksheet . '$' . $column . '$' . $row;
		}

		throw new PHPExcel_Exception('Cell coordinate string can not be a range of cells');
	}

	/**
	 *    Split range into coordinate strings
	 *
	 * @param    string $pRange e.g. 'B4:D9' or 'B4:D9,H2:O11' or 'B4'
	 *
	 * @return    array    Array containg one or more arrays containing one or two coordinate strings
	 *                                e.g. array('B4','D9') or array(array('B4','D9'),array('H2','O11'))
	 *                                        or array('B4')
	 */
	public static function splitRange($pRange = 'A1:A1') {
		// Ensure $pRange is a valid range
		if (empty($pRange))
		{
			$pRange = self::DEFAULT_RANGE;
		}

		$exploded = explode(',', $pRange);
		$counter = count($exploded);
		for ($i = 0; $i < $counter; ++$i)
		{
			$exploded[$i] = explode(':', $exploded[$i]);
		}

		return $exploded;
	}

	/**
	 *    Build range from coordinate strings
	 *
	 * @param    array $pRange Array containg one or more arrays containing one or two coordinate strings
	 *
	 * @return    string    String representation of $pRange
	 * @throws    PHPExcel_Exception
	 */
	public static function buildRange($pRange) {
		// Verify range
		if (!is_array($pRange) || empty($pRange) || !is_array($pRange[0]))
		{
			throw new PHPExcel_Exception('Range does not contain any information');
		}

		// Build range
		$imploded = array();
		$counter = count($pRange);
		for ($i = 0; $i < $counter; ++$i)
		{
			$pRange[$i] = implode(':', $pRange[$i]);
		}
		$imploded = implode(',', $pRange);

		return $imploded;
	}

	/**
	 *    Calculate range boundaries
	 *
	 * @param    string $pRange Cell range (e.g. A1:A1)
	 *
	 * @return    array    Range coordinates array(Start Cell, End Cell)
	 *                    where Start Cell and End Cell are arrays (Column Number, Row Number)
	 */
	public static function rangeBoundaries($pRange = 'A1:A1') {
		// Ensure $pRange is a valid range
		if (empty($pRange))
		{
			$pRange = self::DEFAULT_RANGE;
		}

		// Uppercase coordinate
		$pRange = strtoupper($pRange);

		// Extract range
		if (strpos($pRange, ':') === false)
		{
			$rangeA = $rangeB = $pRange;
		}
		else
		{
			list($rangeA, $rangeB) = explode(':', $pRange);
		}

		// Calculate range outer borders
		$rangeStart = self::coordinateFromString($rangeA);
		$rangeEnd = self::coordinateFromString($rangeB);

		// Translate column into index
		$rangeStart[0] = self::columnIndexFromString($rangeStart[0]);
		$rangeEnd[0] = self::columnIndexFromString($rangeEnd[0]);

		return array($rangeStart, $rangeEnd);
	}

	/**
	 *    Calculate range dimension
	 *
	 * @param    string $pRange Cell range (e.g. A1:A1)
	 *
	 * @return    array    Range dimension (width, height)
	 */
	public static function rangeDimension($pRange = 'A1:A1') {
		// Calculate range outer borders
		list($rangeStart, $rangeEnd) = self::rangeBoundaries($pRange);

		return array(($rangeEnd[0] - $rangeStart[0] + 1), ($rangeEnd[1] - $rangeStart[1] + 1));
	}

	/**
	 *    Calculate range boundaries
	 *
	 * @param    string $pRange Cell range (e.g. A1:A1)
	 *
	 * @return    array    Range coordinates array(Start Cell, End Cell)
	 *                    where Start Cell and End Cell are arrays (Column ID, Row Number)
	 */
	public static function getRangeBoundaries($pRange = 'A1:A1') {
		// Ensure $pRange is a valid range
		if (empty($pRange))
		{
			$pRange = self::DEFAULT_RANGE;
		}

		// Uppercase coordinate
		$pRange = strtoupper($pRange);

		// Extract range
		if (strpos($pRange, ':') === false)
		{
			$rangeA = $rangeB = $pRange;
		}
		else
		{
			list($rangeA, $rangeB) = explode(':', $pRange);
		}

		return array(self::coordinateFromString($rangeA), self::coordinateFromString($rangeB));
	}

	/**
	 *    Column index from string
	 *
	 * @param    string $pString
	 *
	 * @return    int Column index (base 1 !!!)
	 */
	public static function columnIndexFromString($pString = 'A') {
		//	Using a lookup cache adds a slight memory overhead, but boosts speed
		//	caching using a static within the method is faster than a class static,
		//		though it's additional memory overhead
		static $_indexCache = array();

		if (isset($_indexCache[$pString]))
			return $_indexCache[$pString];

		//	It's surprising how costly the strtoupper() and ord() calls actually are, so we use a lookup array rather than use ord()
		//		and make it case insensitive to get rid of the strtoupper() as well. Because it's a static, there's no significant
		//		memory overhead either
		static $_columnLookup = array(
				'A' => 1,
				'B' => 2,
				'C' => 3,
				'D' => 4,
				'E' => 5,
				'F' => 6,
				'G' => 7,
				'H' => 8,
				'I' => 9,
				'J' => 10,
				'K' => 11,
				'L' => 12,
				'M' => 13,
				'N' => 14,
				'O' => 15,
				'P' => 16,
				'Q' => 17,
				'R' => 18,
				'S' => 19,
				'T' => 20,
				'U' => 21,
				'V' => 22,
				'W' => 23,
				'X' => 24,
				'Y' => 25,
				'Z' => 26,
				'a' => 1,
				'b' => 2,
				'c' => 3,
				'd' => 4,
				'e' => 5,
				'f' => 6,
				'g' => 7,
				'h' => 8,
				'i' => 9,
				'j' => 10,
				'k' => 11,
				'l' => 12,
				'm' => 13,
				'n' => 14,
				'o' => 15,
				'p' => 16,
				'q' => 17,
				'r' => 18,
				's' => 19,
				't' => 20,
				'u' => 21,
				'v' => 22,
				'w' => 23,
				'x' => 24,
				'y' => 25,
				'z' => 26
		);

		//	We also use the language construct isset() rather than the more costly strlen() function to match the length of $pString
		//		for improved performance
		if (isset($pString{0}))
		{
			if (!isset($pString{1}))
			{
				$_indexCache[$pString] = $_columnLookup[$pString];

				return $_indexCache[$pString];
			}
			elseif (!isset($pString{2}))
			{
				$_indexCache[$pString] = $_columnLookup[$pString{0}] * 26 + $_columnLookup[$pString{1}];

				return $_indexCache[$pString];
			}
			elseif (!isset($pString{3}))
			{
				$_indexCache[$pString] = $_columnLookup[$pString{0}] * 676 + $_columnLookup[$pString{1}] * 26 + $_columnLookup[$pString{2}];

				return $_indexCache[$pString];
			}
		}
		throw new PHPExcel_Exception("Column string index can not be " . ((isset($pString{0})) ? "longer than 3 characters" : "empty"));
	}

	/**
	 *    String from columnindex
	 *
	 * @param    int $pColumnIndex Column index (base 0 !!!)
	 *
	 * @return    string
	 */
	public static function stringFromColumnIndex($pColumnIndex = 0) {
		//	Using a lookup cache adds a slight memory overhead, but boosts speed
		//	caching using a static within the method is faster than a class static,
		//		though it's additional memory overhead
		static $_indexCache = array();

		if (!isset($_indexCache[$pColumnIndex]))
		{
			// Determine column string
			if ($pColumnIndex < 26)
			{
				$_indexCache[$pColumnIndex] = chr(65 + $pColumnIndex);
			}
			elseif ($pColumnIndex < 702)
			{
				$_indexCache[$pColumnIndex] = chr(64 + ($pColumnIndex / 26)) . chr(65 + $pColumnIndex % 26);
			}
			else
			{
				$_indexCache[$pColumnIndex] = chr(64 + (($pColumnIndex - 26) / 676)) . chr(65 + ((($pColumnIndex - 26) % 676) / 26)) . chr(65 + $pColumnIndex % 26);
			}
		}

		return $_indexCache[$pColumnIndex];
	}

	/**
	 *    Extract all cell references in range
	 *
	 * @param    string $pRange Range (e.g. A1 or A1:C10 or A1:E10 A20:E25)
	 *
	 * @return    array    Array containing single cell references
	 */
	public static function extractAllCellReferencesInRange($pRange = 'A1') {
		// Returnvalue
		$returnValue = array();

		// Explode spaces
		$cellBlocks = explode(' ', str_replace('$', '', strtoupper($pRange)));
		foreach ($cellBlocks as $cellBlock)
		{
			// Single cell?
			if (strpos($cellBlock, ':') === false && strpos($cellBlock, ',') === false)
			{
				$returnValue[] = $cellBlock;
				continue;
			}

			// Range...
			$ranges = self::splitRange($cellBlock);
			foreach ($ranges as $range)
			{
				// Single cell?
				if (!isset($range[1]))
				{
					$returnValue[] = $range[0];
					continue;
				}

				// Range...
				list($rangeStart, $rangeEnd) = $range;
				sscanf($rangeStart, '%[A-Z]%d', $startCol, $startRow);
				sscanf($rangeEnd, '%[A-Z]%d', $endCol, $endRow);
				$endCol++;

				// Current data
				$currentCol = $startCol;
				$currentRow = $startRow;

				// Loop cells
				while ($currentCol != $endCol)
				{
					while ($currentRow <= $endRow)
					{
						$returnValue[] = $currentCol . $currentRow;
						++$currentRow;
					}
					++$currentCol;
					$currentRow = $startRow;
				}
			}
		}

		//	Sort the result by column and row
		$sortKeys = array();
		foreach (array_unique($returnValue) as $coord)
		{
			sscanf($coord, '%[A-Z]%d', $column, $row);
			$sortKeys[sprintf('%3s%09d', $column, $row)] = $coord;
		}
		ksort($sortKeys);

		// Return value
		return array_values($sortKeys);
	}

	/**
	 * Compare 2 cells
	 *
	 * @param    PHPExcel_Cell $a Cell a
	 * @param    PHPExcel_Cell $b Cell b
	 *
	 * @return    int        Result of comparison (always -1 or 1, never zero!)
	 */
	public static function compareCells(PHPExcel_Cell $a, PHPExcel_Cell $b) {
		if ($a->getRow() < $b->getRow())
		{
			return -1;
		}
		elseif ($a->getRow() > $b->getRow())
		{
			return 1;
		}
		elseif (self::columnIndexFromString($a->getColumn()) < self::columnIndexFromString($b->getColumn()))
		{
			return -1;
		}
		else
		{
			return 1;
		}
	}

	/**
	 * Get value binder to use
	 *
	 * @return PHPExcel_Cell_IValueBinder
	 */
	public static function getValueBinder() {
		if (self::$_valueBinder === null)
		{
			self::$_valueBinder = new PHPExcel_Cell_DefaultValueBinder();
		}

		return self::$_valueBinder;
	}

	/**
	 * Set value binder to use
	 *
	 * @param PHPExcel_Cell_IValueBinder $binder
	 *
	 * @throws PHPExcel_Exception
	 */
	public static function setValueBinder(PHPExcel_Cell_IValueBinder $binder = null) {
		if ($binder === null)
		{
			throw new PHPExcel_Exception("A PHPExcel_Cell_IValueBinder is required for PHPExcel to function correctly.");
		}

		self::$_valueBinder = $binder;
	}

	/**
	 * Implement PHP __clone to create a deep clone, not just a shallow copy.
	 */
	public function __clone() {
		$vars = get_object_vars($this);
		foreach ($vars as $key => $value)
		{
			if ((is_object($value)) && ($key != '_parent'))
			{
				$this->$key = clone $value;
			}
			else
			{
				$this->$key = $value;
			}
		}
	}

	/**
	 * Get index to cellXf
	 *
	 * @return int
	 */
	public function getXfIndex() {
		return $this->_xfIndex;
	}

	/**
	 * Set index to cellXf
	 *
	 * @param int $pValue
	 *
	 * @return PHPExcel_Cell
	 */
	public function setXfIndex($pValue = 0) {
		$this->_xfIndex = $pValue;

		return $this->notifyCacheController();
	}

	/**
	 * @deprecated        Since version 1.7.8 for planned changes to cell for array formula handling
	 */
	public function setFormulaAttributes($pAttributes) {
		$this->_formulaAttributes = $pAttributes;

		return $this;
	}

	/**
	 * @deprecated        Since version 1.7.8 for planned changes to cell for array formula handling
	 */
	public function getFormulaAttributes() {
		return $this->_formulaAttributes;
	}

	/**
	 * Convert to string
	 *
	 * @return string
	 */
	public function __toString() {
		return (string)$this->getValue();
	}

}

